A wafer-level camera is a camera having a small footprint that can be utilized in electronic devices having a thin form factor, for example a mobile phone, notebook computer, tablet computer, and the like. Such wafer-level cameras include optics to form an image and an image sensor for sensing the image. To form a high quality image, the optics of the camera module may include several lenses, sometimes separated by spacers, that require precise alignment.
The wafer-level camera is typically manufactured by stacking and bonding wafers having optical components using alignment and bonding techniques. For example, a sensor water having a number of image sensors arranged in an array or grid pattern may be provided first, possibly with a cover glass layer for protection of the sensor substrate. A wafer having an array of lenses, known as a lens plate, is fabricated by providing a water and separately forming a lens surface on each side of the wafer using semiconductor techniques. A lens surface on a first side of the wafer is formed and then a second lens surface is formed on the second side. Each lens of the lens plate is then aligned with one of the image sensors. Separately forming the lens surfaces includes the steps of fabricating and aligning the lens surfaces of the first side with the lens surface of the second side, and such aligning can be difficult and error-prone when done during the fabrication stage.